Sharing in the profits as well as the losses in an investment

Q: My bother passed away and his five kids and widow are in my supervision. Even though I am a lady but Alhamdulillah I did my best. Alhamdulillah now my brothers property problem is also solved and Alhamdulillah they received some money. They are not capable of handling this amount. No one in relatives are responsible enough to keep this Amanath for them. And may Allah Ta'ala forgive me I don't trust anyone for their money. I don't want to keep it in the bank and collect interest on their money. So with several god fearing peoples advise I invested their money in a certain brothers clothes store. He said for every 1 Lakh Rs he will give 1 thousand as profit. He said he can give more than that because he is saving lot more in interest. He said he will fix this minimum amount. And Allah forbid if in case he has loss in his business he will sell his house and give the money back to us. I got everything in writing for my brothers widow and her children's name. Alhamdulillah this brother himself is a very pious person. And spends lots of his time besides business in Dawah work. So mufti sahib please advise me if I did it right?

Preparing in advance for Salaah due to urine problems

Q: Islam is a religion of ease not of hardship, it is very well mentioned in the Qur'an and hadith about this easiness. I am suffering from urine incontinence. I have realised that I am not a mazoor, but for praying one namaaz I have to make wudhu 3 to 4 time and every time I have to wash my private part, whether I pray on time or later I have to face this hardship. It is really very difficult. So why there is hardship when there is so much easiness in Islam? I am missing my salaah because I can't take this hardship. I am really upset with myself because I can't worship my Allah who has given me so much. Please help find a easy way for me.

Performing nafil Salaah in jamaat

Q: During Ramdhaan in the Haramain both at Makkah and Madinah they conduct Tahajjud namaaz in Jamaath during the last 10 days from 1 am to 2.30 am. Following this now a days the same method is being followed in mosques in our country (India) as well and also women participate in this congregation but of course in a enclosure segregated for women. Also now a days women attend Jummah namaaz in mosques on a regular basis. Please give your expert option on these two issues.